Chapter 83: Atrial Fibrillation, Atrial Flutter, and Atrial Tachycardia
A 60-year-old man presents to you in consult after his second episode of atrial fibrillation (AF) in 2 years. Regarding the classification of AF, which is incorrect?
A. Paroxysmal AF is characterized by self-terminating episodes that generally last < 7 days
B. AF that lasts > 7 days is generally termed persistent
C. Long-standing AF may be diagnosed when AF has been continuous for at least 1 year
D. Permanent AF is diagnosed once a patient has failed cardioversion or when further attempts to terminate AF is deemed futile
E. AF may be labeled chronic when a diagnosis of AF has been present for at least 5 years
The answer is E. (Hurst’s The Heart, 14th Edition, Chap. 83). Atrial fibrillation is classified into four categories: paroxysmal, persistent, long-standing persistent, and permanent.1 The definition of chronic AF (option E) varies greatly in the literature, and the term is best avoided. Paroxysmal AF is characterized by self-terminating episodes that generally last < 7 days (most < 24 hours) (option A), whereas persistent AF generally lasts > 7 days (option B) and often requires electrical or pharmacologic cardioversion. Long-standing AF has been continuous for at least a year (option C). Many patients have both paroxysmal and persistent episodes of AF, and in general, we characterize such patients by their more typical form of AF. AF is classified as permanent when a patient has failed cardioversion or when further attempts to terminate the arrhythmia are deemed futile (option D).
The mechanism of AF may be multifactorial. Which one of the following statements regarding the pathophysiology of AF is correct?
A. Rapidly firing ectopic foci in the pulmonary arteries have been shown to be the underlying mechanism of most paroxysmal AF
B. The pulmonary vein musculature of patients with paroxysmal AF may demonstrate an increased effective refractory period and conduction delay
C. In patients with paroxysmal AF, most triggering foci that are mapped during electrophysiologic study occur within the inferior vena cava, the right atrial appendage, and the anterior interventricular vein
D. Rotors or spiral wave reentry has shown importance as a perpetuating mechanism for AF
E. The greater the amount of atrial fibrosis, the more likely is the success of catheter ablation using standard ablation approaches
The answer is D. (Hurst’s The Heart, 14th Edition, Chap. 83) A variety of electrophysiologic and structural factors promote the perpetuation of AF. Recently, rotors or spiral wave reentry has shown importance ...